NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 2: Geometry - Multiple Choice Questions

Question 15

Step 1: A right triangle has one angle of \(90^\circ\).

Step 2: Given \(\angle BAC = 90^\circ\).

So, \(\triangle ABC\) is a right triangle.

Step 3: Also given AD ⟂ BC.

This means the angle at D with BC is a right angle.

Step 4: In \(\triangle ABD\):

\(\angle ADB = 90^\circ\).

So, \(\triangle ABD\) is a right triangle.

Step 5: In \(\triangle ADC\):

\(\angle ADC = 90^\circ\).

So, \(\triangle ADC\) is a right triangle.

Step 6: Count all right triangles.

\(\triangle ABC\) → 1

\(\triangle ABD\) → 1

\(\triangle ADC\) → 1

Total = \(1 + 1 + 1 = 3\).